To know size of first computer, you must choose which computer was first. It was either ENIAC, built by J. Presper Eckert and John Mauchly in 1943, or Atanasoff-Berry Computer, built in 1942. The deciding thing is not year in which each was built, but who officially holds first patent to digital computer and this was decided in a patent trial in 1973.

Controversy

1. Atanasoff and Berry did manufacture initial digital computer, in 1942, but never patented it. Computer sit within basement of Iowa State University physics section mainly forgotten as many nations’ engineering and scientific resources at the time had been going to war effort and building of atomic bomb. The patent office awarded privileges for first digital computer to J. Presper Eckert and John Mauchly depending on their ENIAC design. Though, in 1973 a patent test invalidated those privileges, as judge ruled that ENIAC was depending on design of Atanasoff-Berry Computer.

Weight

2. Atanasoff-Berry Computer slanted 700 lbs. It was composed of 300 vacuum tubes and over 5,000 feet of wire, about a mile. As largest PC at the time, it could do about one floating-point process in about 15 seconds. For comparison, biggest PCs today can do about 10 billion floating-point operations in a second.

Dimension

3. After War World II, Atanasoff-Berry Computer was taken separately and spotted. Though, fairly to prove that Atanasoff-Berry Computer truly did work, Iowa State University built an accurate copy in 1997. The copy stands about as tall as a standard desk. It's about 6 feet wide and 33 inches deep. Original machine was 36 inches deep, too wide to obtain it through a standard university door, which explains why original machine never left basement of physics section. The rebuilding team did not want copy to get caught someplace, so they shorted it by 3 inches. It now tours country as first digital computer.

Materials

4. Atanasoff and Berry built first computer out of current telephone switchboard technology of that time. The switches are still created today, but create of the original vacuum tubes gave way to transistor in early 50s. The Iowa rebuilding team wanted to buy actual vacuum tubes made at the time from antique dealers. Original mechanical parts were also difficult to come by, but rebuilding team managed.

Input & Output

5. As Atanasoff-Berry Computer worked its way through problems, it wanted some kind of medium to record and save middle results. Atanasoff-Berry Computer generated about 1,500 bits of data per second, but there was nothing at the time that could automatically record data at that rate. Atanasoff and Berry resolved problem by coming up with a system of electrostatic punches that would burn a small hole in a running sheet of paper. Remarkable for time, system of zapping reams of paper only failed after in every 10,000 to100, 000 bits of data.